Smarthound cares about your data. Smarthound does not directly handle personal data apart from your email address when you decide to make an account. Nevertheless, all your data is always encrypted while being transmitted online, and all data is encrypted at rest. The data you see in the app – assuming you made an account – is the data stored and accessible by Smarthound. If you didn't make an account, none of the data ever leaves your device. If you log out then your data up to that point is accessible by Smarthound. Any changes you made after going offline or only available on your device.
The app is designed from the ground up to be offline-first. This means you don't get locked in if the Smarthound servers go down. As long as the app continues to work, you have access to the data you entered – whether you are online or not, whether Smarthound is still here or not. It's your data, so special care has been taken to ensure you keep access to it. However, the app is a paid app. This means your payment needs to be kept up-to-date (although your subscription is with Apple/Google, so this is unaffected of whether Smarthound servers are accessible or not and outside our control).